what seismic data, raw data or charts, was collected in the new york
region on 11sep01 that reflects the seismic activity caused by the
collapse of the world trade center towers?  where may that data be
obtained?

Hello pjbell and thank you for the question.

Having researched your question I was surprised to find that quite
alot of study has gone in to this subject.  Here are the results of my
research:

5 Graphs/charts showing seismic activity during the attacks.
(including various links)
http://www.geo.arizona.edu/geophysics/faculty/wallace/WTC/index.html

Unfortunatley only available in the Google cache, at the time of
posting.
"Seismic Observations during September 11, 2001, Terrorist Attack"
http://216.239.53.100/search?q=cache:fjfzXsQy3cYC:www.mgs.md.gov/esic/publications/download/911pentagon.pdf++%22sept+11%22+seismic&hl=en&ie=UTF-8

Several good quality graphs/charts  *NOTE* pdf format.
"Seismic Waves Generated by Aircraft Impacts and Building Collapses at
World Trade Center, New York City."
http://www.ldeo.columbia.edu/LCSN/Eq/20010911_WTC/WTC_LDEO_KIM.pdf

Online News article
"Seismic Stations Record Useful Information on Terrorist Bombings"
http://www.spacedaily.com/news/nuclear-blackmarket-02k.html

Online News article
"Damage to buildings near World Trade Center Towers caused by falling
debris and air pressure wave, not ground shaking, seismologists
report"
http://www.eurekalert.org/pub_releases/2001-11/agu-dtb111501.php

Online News article
"Preliminary measurements made by Lamont-Doherty analysts are
summarized in the Table below: Information Based on Seismic Waves
recorded at Palisades New York"
http://www.firehouse.com/tech/news/2002/0121_terrorist.html


During my research the name of Terry Wallace (University of Arizona)
came up alot.  I would suggest that he is a leading authority on this
subject (if not THE leading authority) and he can be contacted through
his website at the University of Arizona here:
http://www.geo.arizona.edu/geophysics/faculty/wallace/Wallace.html

Thank you for the question, and if you need any clarification
regarding my answer, please do not hesitate to ask.

Best regards

THX1138

Search strategy included:
"sept 11" seismograms 
://www.google.com/search?q=+%22sept+11%22+seismograms+&hl=en&lr=&ie=UTF-8&as_qdr=all&start=10&sa=N

well done, fast and complete

Let me add one more link to the excellent list above, as this is quite
a thorough review of the available seismic data:

http://www.vibrationdata.com/Newsletters/November2001_NL.pdf